Room-to-low temperature thermo-mechanical behavior and corresponding constitutive model of liquid oxygen compatible epoxy composites
Room-to-low temperature thermo-mechanical behavior and corresponding constitutive model of liquid oxygen compatible epoxy composites
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DOI：
10.1016/j.compscitech.2023.110357
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发表时间：
2023-11
影响因子：
9.1
通讯作者：
Yicheng Jiang;Ling Liu;Jia Yan;Zhanjun Wu
中科院分区：
文献类型：
--
作者：
Yicheng Jiang;Ling Liu;Jia Yan;Zhanjun Wu
液氧相容性环氧复合材料（LOC-EP）的室温-低温（RT-LT）力学性能在轻量化液氧罐的强度分析中具有重要意义。本文首先探讨了低温至- 183℃时LOC-EP的拉伸压缩力学行为。结果表明：与常温相比，- 183℃时的拉伸强度、抗压强度和弹性模量分别提高了44%、109%和160%；其次，根据分子链冻结度和屈服面延伸理论，依次得到- 60℃的韧脆转变T和- 90℃的完全脆性T。推导了EP的通用热-力学本构模型，并利用Matlab对C-EP在RT ~ - 183℃范围内的本构模型参数进行了拟合和标定。最后，通过用户子程序将本构模型引入到Abaqus中。一方面，三维单元分析表明，模拟曲线与实验曲线和matlab拟合曲线高度吻合（误差小于3%），具有良好的收敛性和精度。另一方面，拉伸和压缩试件宏观模拟得到的断裂模式也与试验断裂模式一致。
The room-to-low temperature (RT-LT) mechanical behavior of liquid oxygen-compatible epoxy composites (LOC-EP) is of great importance in the strength analysis of lightweight liquid oxygen tanks. This article first explores the tensile-compressive mechanical behaviors of LOC-EP from RT down to −183 °C. The results show that compared with RT, the tensile strength, compressive strength, and elastic modulus at −183 °C increase by 44%, 109%, and 160% respectively. Secondly, based on the theories of molecular chain freezing degree and yield surface extension, a ductile-brittle transition T of −60 °C and a completely brittle T of −90 °C are obtained sequentially. Moreover, a universal thermal-mechanical constitutive model for EP is derived, and the constitutive model parameters of LOC-EP from RT to −183 °C are fitted and calibrated using Matlab. Finally, the proposed constitutive model is introduced into Abaqus through a user subroutine. On the one hand, three-dimensional one-element analyses demonstrate that the simulation curves are highly consistent with the experimental and Matlab-fitted curves (errors less than 3%) with good convergence/accuracy. On the other hand, the fracture modes obtained from macroscopic simulations of tensile and compressive specimens are also coherent with the experimental fracture modes.